As mobile devices have been increasingly developed and the demand for such mobile devices has increased, the demand for batteries has also sharply increased as an energy source for the mobile devices. Accordingly, much research on batteries satisfying various needs has been carried out.
In terms of the shape of batteries, the demand for prismatic secondary batteries or pouch-shaped secondary batteries, which are thin enough to be applied to products, such as mobile phones, is very high. In terms of the material for batteries, on the other hand, the demand for lithium secondary batteries, such as lithium ion batteries and lithium ion polymer batteries, having high energy density, discharge voltage, and output stability, is very high
As energy density and capacity of the secondary battery have been greatly increased, however, a larger amount of heat is generated from the secondary battery during repetitive charge and discharge of the secondary battery and, therefore, the temperature of the secondary battery is excessively increased. As a result, a device may malfunction and operation efficiency of the device may be lowered. In addition, the lifespan of the secondary battery may be greatly reduced.
For this reason, a great number of tests are carried out for products in order to secure optimal operation and safety of the battery. A process of measuring an electrochemical operation state, such as voltage and current, and a physical operation state, such as temperature and pressure, of a test sample using a battery charging and discharging device is included in the tests.
A conventional charging and discharging device has no problem in a case in which current precision of one facility is measured. In a case in which several charging and discharging facilities are to be measured in a limited space, however, precision of the charging and discharging device is greatly lowered due to many internal resistance elements. As a result, precision in charging current of a battery cell is also reduced.
Therefore, there is a high necessity for an apparatus, having a compact size with improved spatial efficiency, which is capable of periodically inspecting precision in charging current of the charging and discharging device.
In addition, there is a high necessity of an inspecting apparatus that is capable of sorting defects of the charging and discharging device before the defects of the charging and discharging device are generated.